Carbureter.



UNITED STATES PATENT OFFICE.

CHARLES H. KIRBY, OF DETROIT, MICHIGAN, ASSIGNOR 'IO DETROIT LUIBBIC ATOB COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OI MICHIGAN.

CABBUBETEB.

Specification of Letters Patent. Patented Jan. 23., 1917.

Application filed September 28, 1915. Serial m. 52,284.

To all whom it may concern:

, to properly proportion To this end I have provided the usual Be it known that I, (lIiAnLns H. KIRBY, a' citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have irwented certain new and useful Improvements in Carbureters, of which the following is a specification, reference being had therein to the accompanying drawings.

,The invention relates to carburetors of that type in which the liquid fuel is metered bymeans automatically controlled by the velocity of the air current in which the liquid is discharged. \Vith 'such constructions it is usual to provide an automaticallyoperating air valve containing an oil discharge nozzle or aspirating tube, and a cooperating metering pin, which varies the area of opening with each position of adjustment of the valve. Where a metering pin with a uniform taper is used, the area of opening increases with the movement of the valve, but it has been found that this does not produce a proportional dischar of the liquid, for the reason that the WS- cosity of the latter retards its flow through a small area. Thus the practical efiect is to produce too lean a mixture at low speeds and too rich a mixture at high speed.

It is the object of the present invention to avoid this defect and to accomplish the result without the necessity of curving or changing the angle of the which is not practical in manufacturing.

meterin pin with the strai ht taper desi ned g th'e discharg of liquid at low speeds, and have associated therewith additional means for restricting the flow of liquid at high speeds. I

In the drawings: Figure -1 is a central section through aportion of a carbureter embodying my invention; and Fig. 2 is an enlarged view of the oil discharge nozzle.

A is the casing containing the mixing chamber B, having its admission port controlled by an automatic valve 0. This valve is provided with an aspirating tube D, which coiiperateswith a metering pin E to vary the area of opening for the oil pro portional to the movement of the valve. The construction is such that variations in the position of the valve G will produce a proportionate mixture of oil and the liquid metering pin,-

when the engine is-running atlow or moderate speed. i

With the construction as thus far -described, when the engine is running at relatively high speed there will be a' d proportionate discharge of the-liquid pr ncing .an

vided an additional means of'restricting the flow, comprising a restricted orifice F,

per endof the aspiratpreferably at the u an areaas to limit the ing tube, and of suc maximum discharge of liquid therethrough to correspond to t e maximum flow of air. Above and below this restriction the tube is preferably flared, as indicated at G and H, so as to avoid the forming of eddies.

In operation, when the engine is running at low speed the area of the restriction'F is greater than the opening controlled'by the meter n pm, and consequently has no effect in restricting the flow. As the speed in-- creases, however, the restriction imposed by the port F is increased, thereby maintaining a substantially proportionate discharge throughout the entire range of adjustment.

What I claim'as my invention is: 1. In a carbureter, the combination. with an automatic air valve, an aspirating tube carried thereby and a cooperating meterin fl restricting the discharge 0 tube, of.

carried thereby and a cotiperatingmetering" the area of inlet opening to said tube in ifl'erent positions of adjustment of the valve, of a restriction in said aspirating tube proportioned" to limit the maximum discharge ofliquid and to be relatively inoperative at restricted positions of adjustment of said metering pin.

3. In a carbureter, the combination with an automatic air valve, an aspirating tube carried thereby and. a cooperating metering pin for varying the inlet of the liquid fuel, of a restriction located at the discharge mouth of said aspirating tube pro ortioned to limit the maximum dischar e 0 liquid.

4. In a carbureter, the com ination with pin for varyin over-rich mixture. I have therefore pro-j an automatic air valve, of an aspirating tube a restriction located at the discharge I l'lOuth 10 and cooperating metering pin one of which thereof proportioned to limit the maximum is controlled by said valve, said tube'having discharge of liquid.

a restriction at one point and being flared at In testimony whereof I affix my signature 5 each side of the restriction. in presence. of two witnesses.

5. In a carbureter, the combination with CHARLES H. KIRBY. an automatic air valve, of an aspirating tube Witnesses: and cooperating metering pin one of Which JAMES P. BARRY,

is controlled by said valve, said tube having PHYLLIS CoBURN. 

